The present invention relates to improvements in apparatus for making a continuous tobacco stream, and more particularly to improvements in apparatus for converting a relatively wide but thin mass of comminuted tobacco into a narrow tobacco stream. Still more particularly, the invention relates to improvements in tobacco stream making apparatus of the type disclosed in commonly owned British Pat. No. 1,106,498.
British Pat. No. 1,106,498 discloses an apparatus wherein a foraminous intermediate conveyor feeds tobacco into a channel defined by three endless belt conveyors. The channel has a rectangular cross-sectional outline and two of the three belt conveyors have stretches which converge in the direction of tobacco transport on the intermediate conveyor so that the width of the tobacco stream which accumulates in the channel decreases with attendant increase in density. The resulting relatively narrow but relatively dense stream is draped into a web of cigarette paper to form a continuous rod which is thereupon severed at regular intervals to yield plain cigarettes, cigarillos or the like. The web of wrapping material is advanced by one of the belt conveyors.
The just described stream forming apparatus is not entirely satisfactory because particles of tobacco are likely to be caught between neighboring conveyors and to be withdrawn from the condensed tobacco stream in the region where the belt conveyors are trained over pulleys or sheaves. Furthermore, the homogeneousness of the tobacco stream is not sufficient to warrant immediate draping into cigarette paper or the like without further equalization of density. Moreover, the apparatus reduces the size of a relatively high percentage of tobacco shreds.